Contrary to conventional wisdom, a researcher said Friday, menopause does not appear to cause depression and hormone replacement therapy is probably unnecessary for most wom-en going through natural menopause.

John McKinlay, director of the New England Research Institute, said a large, long-term study found no association between natural menopause and depression and strongly suggests that most estrogen replacement therapy is unneeded.Other researchers, however, challenged the conclusion that estrogen replacement is unnecessary, saying it protects women from heart disease and the bone-thinning disease osteoporosis.

"To make a general statement that women shouldn't go on estrogen is an enormous public health mistake," said Dr. Machelle Seibel, director of reproductive endocrinology at Beth Israel Hospital and a professor of gynecology at Harvard Medical School in Boston.

Menopause usually occurs when women reach their 50s and their ovaries stop producing the hormone estrogen. This drop in estrogen has been associated with a variety of problems, including hot flashes, vaginal dryness and depression. About 5 million American women take estrogen pills to relieve the symptoms.

A new product, a stick-on patch that diffuses estrogen through the skin, is also on the market.

Women undergo artificial menopause when their ovaries are removed surgically.

McKinlay's findings, reported at a meeting of the Society of Behavioral Medicine, were culled from the Massachusetts Women's Health Study. The ongoing study, the largest of its kind, involves a random sample of 2,500 women who have been followed since they were ages 45 to 55 in 1981.

When the study began, none of the women had gone through menopause and about 10 percent were suffering from depression. After going through natural menopause, there was no increase in the percentage of women with depression.